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2

Migration of software part of the question to mathematica.SE?
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Qmechanic♦May 6 '12 at 9:13

i just want the equation that would give me the required plot.
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The-Ever-KidMay 6 '12 at 9:26

Well you can easily change range of your plots in Mathematica, have you tried with that?
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dingo_dMay 6 '12 at 9:47

@Qmechanic NO..... maybe its $\frac{kQ}{x^2+y^2}$ dingo_d the range of my function is infinity i want the function to change a bit so that it tapers more steeply and makes a point fairly earlier than infinity
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The-Ever-KidMay 6 '12 at 10:29

This seems to be a question about how to reproduce the desired plot in Mathematica, rather than a plot about making electric equipotential lines (which you've shown you're able to do), so I'll see if the Mathematica mods want it.
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David Z♦May 7 '12 at 5:17

This looks right, you can change the z range so it will look more 'steeper': PlotRange -> {{-1, 1}, {-1, 1}, {0, -20}} You can also change opacity and play with Mesh to get circles.
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dingo_dMay 6 '12 at 14:49